The invention relates to improvements in apparatus for processing webs or strips or photosensitive material in photographic processing laboratories and similar establishments.
The treatment of films in photographic processing laboratories is being automated to a progressively increasing extent in order to save labor and time and to thus reduce the cost of development, printing and other processing. A modern photographic processing laboratory operates in such a way that the exposed customer films are admitted at one end of a production line and the other end of the production line discharges exposed and developed photographic films (often cut up into sections each of which contains a relatively small number of film frames) and the corresponding prints on exposed and developed photographic paper. Such laboratory no longer relies on rolling up of exposed films between the inlet and the outlet of the production line, and this holds equally true for the manipulation of photographic paper. In other words, once a film has been admitted into a production line, it is caused to advance along a predetermined path without being convoluted onto the cores of reels, bobbins or like storing devices, and this also applies for the manipulation of webs of photographic paper which is to yield prints of exposed and developed film frames. Laboratories of the above outlined character are known as maxilabs. A person at the inlet of a production line inserts successive cartridges with exposed but undeveloped customer film, and the film is thereupon automatically withdrawn from the respective cassette, advanced through one or more monitoring stations, through a developing station and through a copying station. A large number of films can be spliced together end-to-end prior to entering the developing station. The treatment of photographic papers is automated to a similar extent. Such treatment involves developing of exposed photographic paper and subdivision of developed paper into discrete prints. A person at the outlet of the production line introduces the exposed photographic films and the corresponding prints into the pockets of envelopes which are thereupon shipped to or picked up by dealers or customers.
In order to achieve additional savings in space and equipment, it was already proposed to assemble two or more maxilabs in such a way that they operate in parallel and can employ common developing tanks, fixing tanks, rinsing tanks and/or other treating units. For example, each tank for the development of films or photographic paper can be designed to permit the establishment of paths for two or more webs of photosensitive material.
A drawback of heretofore known combined maxilabs wherein at least one treating unit is common to a plurality of running webs of photosensitive material is that the entire production line must be shut down if the equipment for the treatment of a single web happens to be defective or requires attention of a nature which necessitates stoppage of the transporting system for the respective web. This entails considerable losses in output because any stoppage of a single web necessitates simultaneous stoppage of each other web.